Add Redhat6 to official build of core-setup (#3017)
Add Redhat6 to official build of core-setup (#3017)

* Add Redhat6 to official build of core-setup

Add Redhat6 to official build of core-setup. As it's not a portable
build, it's parameter is different from rhel.7.2-x64.

* Chang the Rid name.

Chang the Rid name as we don't have a RID for 6.9.

* Update Centos 6 dockertag

Update Centos 6 dockertag

rakeshsinghranchi/core-setup,chcosta/core-setup,zamont/core-setup,zamont/core-setup,MichaelSimons/core-setup,ericstj/core-setup,wtgodbe/core-setup,chcosta/core-setup,chcosta/core-setup,weshaggard/core-setup,rakeshsinghranchi/core-setup,wtgodbe/core-setup,MichaelSimons/core-setup,ericstj/core-setup,chcosta/core-setup,crummel/dotnet_core-setup,zamont/core-setup,steveharter/core-setup,ericstj/core-setup,zamont/core-setup,crummel/dotnet_core-setup,weshaggard/core-setup,steveharter/core-setup,wtgodbe/core-setup,MichaelSimons/core-setup,wtgodbe/core-setup,zamont/core-setup,crummel/dotnet_core-setup,rakeshsinghranchi/core-setup,steveharter/core-setup,steveharter/core-setup,chcosta/core-setup,ericstj/core-setup,wtgodbe/core-setup,MichaelSimons/core-setup,steveharter/core-setup,ericstj/core-setup,weshaggard/core-setup,MichaelSimons/core-setup,crummel/dotnet_core-setup,crummel/dotnet_core-setup,steveharter/core-setup,rakeshsinghranchi/core-setup,rakeshsinghranchi/core-setup,weshaggard/core-setup,ericstj/core-setup,wtgodbe/core-setup,rakeshsinghranchi/core-setup,zamont/core-setup,weshaggard/core-setup,chcosta/core-setup,weshaggard/core-setup,MichaelSimons/core-setup,crummel/dotnet_core-setup